Hey all
I have a supersonic 22 combo. Every now and then when I turn it out it has a loud hiss which is on the reverb channel. If i turn the reverb down it goes away. This only happens like 1 in every 10 times i turn the amp on.
If I give the amp a nudge or lift it up a little and put it down, the reverb will clang and the noise go away.

things i have done to try and resolve:
swap the 2 reverb tubes around.
re-route the reverb cable further away from the transformer.
Check all connections with the tank and amp.

So my next step was to buy some new ECC81 tubes for the reverb, but I am averse to doing this as due to the intermittent issue I am not sure this is going to resolve it.

Any ideas what else it might be?
Thanks!
B